Icelandic tephrochronology - matching the provenance of proximal and distal volcanic glasses using La-ICPMS trace element data

Abstract : Thorarinsson (1944) pioneered the use of tephrochronology and its application in NW Europe. The basis of this chronological tool is the use of time-parallel marker tephra (i.e., ash <2mm) horizons to correlate proximal volcanic deposits with distal tephras found in marine-lacustrine-ice cores and terrestrial sequences. The trace element geochemistry of volcanic glasses [determined by LA-ICPMS] offers an improved diagnostic tool for matching the juvenile components of proximal and distal tephras and has considerable potential for assigning provenance to cryptotephras (<100 microns) provided they are of sufficient size and thickness.